Cloning and nucleotide sequencing of a Staphylococcus aureus gene encoding a branched-chain-amino-acid transporter.
We recently characterized a transposon-induced NaCl-sensitive mutant of Staphylococcus aureus (U. Vijaranakul, M. J. Nadakavukaren, D. O. Bayles, B. J. Wilkinson, and R. K. Jayaswal, Appl. Environ. Microbiol. 63:1889-1897, 1997). To further characterize this mutant, we determined the nucleotide sequence at the insertion site of the transposon on the S. aureus chromosome. Nucleotide sequencing revealed a 1,326-bp open reading frame (ORF442) encoding a hydrophobic 442-amino-acid polypeptide with a calculated molecular mass of 49,058 Da. The hydrophilicity profile of the gene product revealed the existence of 12 hydrophobic domains predicted to form membrane-associated alpha-helices. Comparison of the amino acid sequence of ORF442 with amino acid sequences in the GenBank database showed extensive homology with the branched-chain-amino-acid transport genes of gram-positive and gram-negative bacteria. This is the first brnQ gene in staphylococci to be described.
Vijaranakul
U
U
Department of Biological Sciences, Illinois State University, Normal 61790-4120, USA.
Xiong
A
A
Lockwood
K
K
Jayaswal
R K
RK
D000483:Alleles; D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems; D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000235:genetics*
D026905:Amino Acid Transport Systems; D000597:Amino Acids, Branched-Chain; D002352:Carrier Proteins; D012965:Sodium Chloride